Add new background abort type.

chrome/browser/page_load_metrics/metrics_web_contents_observer.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 
 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utility>
@@ skipping 405 matching lines @@
 
 void PageLoadTracker::WebContentsHidden() {
   // Only log the first time we background in a given page load.
   if (background_time_.is_null()) {
     // Make sure we either started in the foreground and haven't been
     // foregrounded yet, or started in the background and have already been
     // foregrounded.
     DCHECK_EQ(started_in_foreground_, foreground_time_.is_null());
     background_time_ = base::TimeTicks::Now();
     ClampBrowserTimestampIfInterProcessTimeTickSkew(&background_time_);
+    // Though most cases where a tab is backgrounded are user initiated, we
+    // can't be certain that we were backgrounded due to a user action. For
+    // example, on Android, the screen times out after a period of inactivity,
+    // resulting in a non-user-initiated backgrounding.
+    const bool abort_is_user_initiated = false;
+    NotifyAbort(ABORT_BACKGROUND, abort_is_user_initiated, background_time_,
+                true);
   }
 
   for (const auto& observer : observers_)
     observer->OnHidden();
 }
 
 void PageLoadTracker::WebContentsShown() {
   // Only log the first time we foreground in a given page load.
   if (foreground_time_.is_null()) {
     // Make sure we either started in the background and haven't been
@@ skipping 662 matching lines @@
     content::NavigationHandle* navigation_handle) const {
   DCHECK(navigation_handle->IsInMainFrame());
   DCHECK(!navigation_handle->HasCommitted() ||
          !navigation_handle->IsSamePage());
 
   return BrowserPageTrackDecider(embedder_interface_.get(), web_contents(),
                                  navigation_handle).ShouldTrack();
 }
 
 }  // namespace page_load_metrics